Virtual Private Server User Guide

Internet and UNIX Basics

more: Displays the contents of a text file, or the output of a program, and waits for 

you to ask for more by pressing the space bar if the text is larger than your display. 

It is one of several commands known as pagers because it breaks the displayed 

information up into pages. Other popular pagers include less and most. 

pico: Starts the pico online text editor. An editor is a program that allows you to 

edit text files on your virtual server  a task that you will do often. Many beginners 

find pico to be the easiest editor to learn, although more experienced users often 

prefer the advanced capabilities provided by the vi editor, which is a bit more 

complex to learn.chown: Changes ownership of a file. UNIX files and directories 

are "owned" by both a user and a group. Chown allows you to change both the 

user and group owner of a file, a directory, or a directory and its contents.

chmod: Changes permissions on a file. UNIX files and directories have 

"permissions"   that is, different people are allowed to have different types of 

access to a file or directory based on the permissions that the file or directory has 

been given. 

vi: Not necessarily for the faint of heart, this very powerful full screen editor is 

standard on all UNIX systems. Due to its complexity, we cannot fully cover its use 

in this guide. For more in depth information, you may wish to refer to O Reilly, 

which has published several books on the vi editor.

ps: Short for process status, this is a very useful command, which shows you 

exactly what processes are running on your virtual computer. (Run the command 

man ps for more info). 

Ownership and Permissions

Your VPS server is a multi user environment. It handles multiple users all working 

simultaneously on completely unrelated tasks. The system is responsible for 

properly sharing and managing requests for hardware devices such as memory, 

disk access, network connectivity and CPU time appropriately to each user. Every 

user on the system also belongs to one or more user groups.

Because the system is capable of supporting multiple users, everything the 

system manages has an owner, a group, and a set of permissions governing who 

can read, write, and execute the resource. Most of the work you will do with 

ownership and permissions will be on files and directories. 

When listing files with the ll alias (or the ls  lA command), information about the 

owner, group and permissions of the file are included in the list, along with 

information about the file s size and when it was last modified. For example, the 

following command displays information about a file named aliases in the current 

directory:

> ll aliases

 rw rw r    1  root  mailadmin  1459  Jan 21  06:46  aliases

Technical Training Department

August 2004

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